Abstract
A radio frequency rotary coupler with its power dividers/couplers separated among multiple circuit layers that are axially stacked and interconnected using coaxial feeds. This architecture allows for multiple layers of circuits with minimal outside diameter and while minimizing increase in axial length. The coupler includes a stator, rotor, and dynamic capacitive ring. The stator includes at least a first stator circuit layer with a primary stator power divider (SPD), a second stator circuit layer with at least one secondary SPD, and stator coaxial feeds coupling the primary SPD and the secondary SPD(s). The rotor includes a first rotor circuit layer with a primary rotor power divider (RPD), a second rotor circuit layer with at least one secondary RPD, and rotor coaxial feeds coupling the primary RPD and the secondary RPD(s). The dynamic capacitive ring couples the stator and the rotor via the secondary SPD(s) and RPD(s).
Claims
1. A radio frequency rotary coupler comprising: a stator including: a plurality of stator circuit layers; a plurality of stator power dividers (SPDs), each SPD mounted on a particular one of the plurality of stator circuit layers, the plurality of SPDs including at least a primary SPD, a secondary SPD, and a tertiary SPD; and a stator coaxial feed set connecting and extending from the primary SPD to the tertiary SPD via the secondary SPD; wherein the plurality of stator circuit layers are stacked axially and interconnected using the stator coaxial feed set; a rotor including: a plurality of rotor circuit layers; a plurality of rotor power dividers (RPDs), each RPD mounted on a particular one of the plurality of rotor circuit layers, the plurality of RPDs including at least a primary RPD, a secondary RPD, and a tertiary RPD; and a rotor coaxial feed set connecting and extending from the primary RPD to the tertiary RPD via the secondary RPD; wherein the plurality of rotor circuit layers are stacked axially and interconnected using the rotor coaxial feed set; and a dynamic capacitive ring coupling the stator and the rotor via the tertiary SPD and the tertiary RPD.
2. A radio frequency rotary coupler as in claim 1 further comprising a stator feed connected to the primary SPD.
3. A radio frequency rotary coupler as in claim 1 further comprising a rotor feed connected to the primary RPD.
4. A radio frequency rotary coupler as in claim 1 wherein the plurality of stator circuit layers and the plurality of rotor circuit layers are housed within dielectric supports having an outside diameter less than one inch.
5. A radio frequency rotary coupler comprising: a stator including (a) a first stator circuit layer including a primary stator power divider (SPD), (b) a second stator circuit layer including at least one secondary SPD, (c) at least one tertiary SPD, (d) first stator coaxial feeds coupling the primary SPD and the at least one secondary SPD, and (e) second stator coaxial feeds coupling the at least one secondary SPD and the at least one tertiary SPD; a rotor including (a) a first rotor circuit layer including a primary rotor power divider (RPD), (b) a second rotor circuit layer including at least one secondary RPD, (c) at least one tertiary RPD, (d) first rotor coaxial feeds coupling the primary RPD and the at least one secondary RPD, and (e) second rotor coaxial feeds coupling the at least one secondary RPD and the at least one tertiary RPD; and a dynamic capacitive ring coupling the stator and the rotor via the at least one tertiary SPD and the at least one tertiary RPD.
6. A radio frequency rotary coupler as in claim 5 wherein at least the primary SPD, the at least one secondary SPD, the primary RPD, and the at least one secondary RPD are housed in dielectric supports.
7. A radio frequency rotary coupler as in claim 6 wherein the dielectric supports housing the primary SPD and the at least one secondary SPD are stacked axially, and the dielectric supports housing the primary RPD and the at least one secondary RPD are stacked axially.
8. A radio frequency rotary coupler as in claim 6 wherein each secondary SPD and secondary RPD is housed in a corresponding dielectric support.
9. A radio frequency rotary coupler as in claim 5 further comprising a stator feed connected to the primary SPD and a rotor feed connected to the primary RPD.
10. A radio frequency rotary coupler comprising: a stator including (a) a first stator circuit layer including a primary stator power divider (SPD), (b) a second stator circuit layer including at least one secondary SPD, and (c) stator coaxial feeds coupling the primary SPD and the at least one secondary SPD; a rotor including (a) a first rotor circuit layer including a primary rotor power divider (RPD), (b) a second rotor circuit layer including at least one secondary RPD, and (c) rotor coaxial feeds coupling the primary RPD and the at least one secondary RPD; and a dynamic capacitive ring coupling the stator and the rotor via the at least one secondary SPD and the at least one secondary RPD.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The foregoing will be apparent from the following more particular description of example embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating embodiments of the present invention.
[0010] FIG. 1 is a schematic diagram illustrating a view of an example previous radio frequency rotary coupler.
[0011] FIG. 2 is a schematic diagram illustrating another view of the example previous radio frequency rotary coupler of FIG. 1.
[0012] FIG. 3 is a simplified schematic diagram illustrating one side of the example previous radio frequency rotary coupler of FIG. 1.
[0013] FIG. 4 is a simplified schematic diagram illustrating one side of an example radio frequency rotary coupler according to the present invention.
[0014] FIG. 5 is a simplified schematic diagram illustrating one side of the example radio frequency rotary coupler of FIG. 4.
[0015] FIG. 6 is a schematic diagram illustrating a view of an example radio frequency rotary coupler according to the present invention.
[0016] FIG. 7 is a schematic diagram illustrating another view of the example radio frequency rotary of FIG. 6.
DETAILED DESCRIPTION OF THE INVENTION
[0017] A description of example embodiments of the invention follows. The description illustrates the disclosed configuration and demonstrates the downsizing capability of the new design.
[0018] FIG. 1 is a schematic diagram illustrating a view of an example previous radio frequency rotary coupler 100. As described above, in order for RF energy to be transmitted between the rotating and stationary sections of a rotary coupler 100, the energy is often be fed onto a dynamic capacitive ring. In prior approaches, corporate feed assemblies are constructed radially, with the number of power feeds doubling with each additional circuit path. In the example previous radio frequency rotary coupler of FIG. 1, the RF energy is fed from the stator 105 onto a dynamic capacitive ring 205 (FIG. 2) using eight coaxial power feeds 210 (FIG. 2), and fed to the rotor 110 using a corresponding eight coaxial feeds 215a-h (FIG. 2). Dividing the RF power from a stator input 115 to the eight stator feeds 210 (FIG. 2) is accomplished on the stator side using a primary power divider/combiner 120, two secondary power dividers/combiners (not shown), and four tertiary power dividers/combiners (not shown). The RF energy is then passed across the dynamic capacitive ring 205 to the eight rotor feeds 215a-h. On the rotor side, the power is then combined from the eight rotor feeds 215a-h using four tertiary power dividers/combiners 135a-d, two secondary power dividers/combiners 130a,b, and a primary power divider/combiner 125. The RF energy is them passed to the rotor feed 140. It should be understood that power can flow either from the stator side to the rotor side, or from the rotor side to the stator side. A given power divider/combiner acts either as a power divider or a power combiner depending on the direction of such energy flow, as should be understood by one of ordinary skill in the art. For the sake of convenience and readability, a power divider/combiner may be referred to herein simply as either a power divider or power combiner.
[0019] FIG. 2 is a schematic diagram illustrating another view of the example previous radio frequency rotary coupler 100 of FIG. 1. FIG. 2 provides a better view of the dynamic capacitive ring 205, the eight stator feeds 210, and the eight rotor feeds 215a-h.
[0020] FIG. 3 is a simplified schematic diagram illustrating one side of the example previous radio frequency rotary coupler 100 of FIG. 1. For a given side of the previous radio frequency rotary coupler 100 (either the stator 105 or rotor 110 side), the power divider components can be schematically shown as in FIG. 3. For simplicity, FIG. 3 shows the rotor 110 side. The example rotor side includes a primary power divider 125, two secondary power dividers 130a,b, four tertiary power dividers 135a-d, and eight rotor feeds 215a-h, each coupled as shown using appropriate circuitry. As can be seen in FIG. 3, the amount of area needed on the dielectric support to accommodate the circuitry according to this design can be large.
[0021] FIG. 4 is a simplified schematic diagram illustrating one side of an example radio frequency rotary coupler according to the present invention. As described above, according to the concepts of the present invention, each layer of power dividers can be placed on its own circuit layer. These layers may then be axially stacked and interconnected using coaxial feeds. This architecture allows for multiple layers of circuits with minimal outside diameter. The embodiment shown in FIG. 4 includes three circuit layers 405a-c of a stator side, for example, of the example radio frequency rotary coupler. The layers are shown unstacked for visibility. The first circuit layer 405a includes a primary divider 410 coupled to two coaxial feed 430a,b that lead to two secondary power dividers 415a,b. A second circuit layer 405b includes the two secondary power dividers 415a,b coupled to four coaxial feeds 435a-d that lead to four tertiary power dividers 420a-d. The third circuit layer 405c includes the four tertiary power dividers 420a-d coupled to eight coaxial feeds 425a-h that lead to a dynamic capacitive ring (not shown). Each circuit layer 405a-c includes dielectric material suitable for containing the circuit components.
[0022] FIG. 5 is a simplified schematic diagram illustrating one side of the example radio frequency rotary coupler of FIG. 4. The three layers 405a-c are shown transparently to illustrate the overlapping arrangement of the circuit, and to show how the multi-layer approach can, thus, result in significant space savings.
[0023] FIG. 6 is a schematic diagram illustrating a view of an example radio frequency rotary coupler 600 according to the present invention. The illustrated rotary coupler 600 includes a stator side having a first circuit layer 605 and a two-part second circuit layer 610a,b. The first circuit layer 605 includes a primary power divider 640 that passes energy to the two-part second circuit layer 610a,b. The two-part second circuit layer 610a,b includes two secondary power dividers 645a,b (in this example, one secondary power divider for each part of the two-part circuit layer) that pass energy to four tertiary power dividers 650a-d via coaxial feeds 705a-d (FIG. 7). The tertiary power dividers 650a-d divide and pass the RF energy directly to a dynamic capacitive ring 625. The energy is then passed to four tertiary power dividers 665a-d on the rotor side of the rotary coupler 600. The tertiary power dividers 665a-d combine and pass the RF energy via coaxial feeds 710a-d (FIG. 7) to two secondary power dividers 660a,b on a two-part second circuit layer 620a,b of the rotor side. The secondary power dividers 660a,b combine and pass the energy to a primary power divider 655 on a first circuit layer 615 of the rotor side, which passes the energy to a rotor feed 635 as output.
[0024] FIG. 7 is a schematic diagram illustrating another view of the example radio frequency rotary 600 of FIG. 6. FIG. 7 provides a better view of coaxial feeds 705a-d and coaxial feeds 710a-d. It should be appreciated that multiple variations of the embodiment disclosed in FIGS. 6 and 7, for example, can exist that fall within the scope of the appended claims. For example, the coupler can include any number of circuit layers, and is not limited to the embodiments having two or three layers as shown. Further, the second circuit layer (or any of the circuit layers) can be formed of a single part (as shown in FIG. 4, for example) or can include multiple parts (as shown in FIG. 6, for example). Further, the tertiary power dividers (or last-in-line power dividers for couplers with additional layers) can be coupled directly to the dynamic capacitive ring (as shown in FIG. 6, for example), or can be coupled to the ring via coaxial feeds (as shown in FIG. 4, for example).
[0025] While this invention has been particularly shown and described with references to example embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.
